Parenteral solutions broadly cover fluid replacement, electrolyte replacement and are vehicles for drug medication. Solutions include blood plasma, platelets, red cells, kidney dialysis solutions, saline solutions and nutritional products. These solutions were initially bottled in glass, however, with the introduction of the collapsible parenteral solution bag some years ago, airborne contamination was significantly reduced since the flexible bags empty without outside air entering the system.
The general requirements of a resin used in the manufacture of the parenteral solution bags include flexibility, clarity, toughness at low temperatures, heat sealability, good processability, moisture vapor permeability resistance and ability to be sterilized. The industry is presently employing a highly plasticized PVC film for this purpose. Although this resin does meet most of the requirements, a material is preferred that has little or no plasticizer. Also the PVC film is not very resistant to moisture vapor permeability, and consequently, the continuing loss of moisture of the parenteral solutions reduces their storage life considerably. Therefore, it is required that the bag be sealed within an overpouch made from a film resin designed to have a low water vapor transmission rate (WVTR). Currently the overpouch film is made from a blend of high density polyethylene and butyl rubber and been extruded into film of a thickness of about 4-5 mil to provide the necessary WVTR. This thickness is usually more than needed for physical strength and adds to the cost of the assembly. Another drawback of the overpouch resin is that it lacks the desired clarity, an important property needed for easy and correct identification of the contents of the inner bag.
It is therefore an object of the present invention to provide a resin formulation which is suitable in the manufacture of sterilizable overpouch films of improved clarity and moisture vapor permeability resistance.
It is also an object of the present invention to provide a film useful in the manufacture of sterilizable, collapsible bags for direct and for indirect containment of parenteral solutions.
It is a further object of the invention to provide an improved collapsible intravenous bag assembly.
Other objects are readily determined from a reading of the specification and claims.